This special supplemental issue of the Journal of Physical Activity and Health includes original research on a variety of topics, including physical activity questionnaires, pedometers and accelerometers, and physical activity among older adults and adolescents.

Validity and reliability of a School Travel Survey
Kelly R. Evenson, Brian Neelon, Sarah C. Ball, Amber Vaughn, and Dianne S. Ward

The Effect of Question Order on Reporting Physical Activity and Walking Behavior
Brent Hutto, Patricia A. Sharpe, Michelle L. Granner, Cheryl L. Addy, and Steven Hooker

Assessment of Sedentary Behavior With the International Physical Activity Questionnaire
Dori E. Rosenberg, Fiona C. Bull, Alison L. Marshall, James F. Sallis, and Adrian E. Bauman

The New Zealand Physical Activity Questionnaires: Validation by Heart-Rate Monitoring in a Multiethnic Population
Karen L. Moy, Robert K. Scragg, Grant McLean, and Harriette Carr

Test-Retest Reliability of a Preadolescent Environmental Access to Physical Activity Questionnaire
Heather Elizabeth Erwin

Physical Activity Behavior of Dog Owners: Development and Reliability of of the Dogs and Physical Activity (DAPA) Tool
Hayley E, Cutt, Billie Giles-Corti, Matthew W. Knuiman, and Terri J. Pikora

Differences in School-Day Patterns of Daily Physical Activity in Girls According to Level of Physical Activity
Jorge Mota, Pedro Silva, Luísa Aires, Maria Paula Santos, José Oliveira, and José C. Ribeiro

Use of Accelerometers in a Large Field-Based Study of Children: Protocols, Design Issues, and Effects on Precision
Calum Mattocks, Andy Ness, Sam Leary, Kate Tilling, Steven N. Blair, Julian Shield, Kevin Deere, Joanne Saunders, Joanne Kirkby, George Davey Smith, Jonathan Wells, Nicholas Wareham, John Reilly, and Chris Riddoch

Estimating Physical Activity From Incomplete Accelerometer Data in Field Studies
Sofiya Alhassan, John R. Sirard, Tirzah R. Spencer, Ann Varady, and Thomas N. Robinson

BMI-Referenced Cut Points for Pedometer-Determined Steps per Day in Adults
C. Tudor-Locke, D.R. Bassett Jr., W.J. Rutherford, B.E. Ainsworth, C.B. Chan, K. Croteau, B. Giles-Corti, G. Le Masurier, K. Moreau, J. Mrozek, J.-M. Oppert, A. Raustorp, S.J. Strath, D. Thompson, M.C. Whitt-Glover, B. Wilde, and J.R. Wojcik

Pedometer-Determined Physical Activity Levels of Adolescents: Differences by Age, Sex, Time of the Week, and Transportation Mode to School
Maea Hohepa, Grant Schofield, Gregory S. Kolt, Robert Scragg, and Nick Garrett

Pedometer-Determined Physical Activity, BMI, and Waist Girth in 7- to 16-Year-Old Children and Adolescents
Beth Hands and Helen Parker

Validity of 2 Devices for Measuring Steps Taken by Older Adults in Assisted-Living Facilities
Randall J. Bergman, David R. Bassett Jr., and Diane A. Klein

Experiences of Route and Task-Based Walking in a University Community: Qualitative Perspectives in a Randomized Control Trial
Nicholas Gilson, Jim McKenna, and Carlton Cooke

A Descriptive Examination of the Most Frequently Used Activity Settings in 25 Community Parks Using Direct Observation
Julian A. Reed, Cheryl-Anne Arant, Princess Wells, Katherine Stevens, Sandra Hagen, and Holly Harring